1. Technical Field of the Invention
The present invention relates to cramping structure of guide bar for a head carriage in a magnetic disk dive. Specifically, it relates to the cramping structure of guide bar in which the guide bar is cramped by cramp arms provided on a long plate-shaped guide bar cramp.
2. Related Art
FIG. 5 shows a conventional cramping structure of guide bar. In this structure, stress receiving members 2 and 3 arm projectingly provided on a frame 1 of a magnetic disk drive. Whe the frame 1 is firmed by press molding, the stress receiving members 2, 3 are firmed by punching predetermined positions of a steel plate which is a material of the frame 1.
Also, through holes 5 and 5 are opened up on a slide table 4 of a head carriage. At the time of assembling, a guide bar 6 is inserted into the through holes 5, 5 in advance, and both edges of the guide bar 6 am abutted against the stress receiving members 2, 3 from outside (in FIG. 6, right side), then a guide bar cramp 7 is mounted along the guide bar 6 from outside.
A base 8 of the guide bar cramp 7 is formed in long plate-like, and cramp arm 9 and 9 are projectingly provided on inside (in FIG. 6, left side) of both edges of the guide bar cramp 7 respectively. The cramp arms 9, 9 are bent at a folding line 10 to erect upwards with regard to the base 8. Here, while no stress is applied to the cramp arms 9, 9 at the time of before cramping, the inclined range of the cramp arms 9, 9 are gentle more than that shown in the FIG. 5. The cramp arms 9, 9 are abutted against both edges of the guide bar 6 from outside above when the guide bar cramp 7 is mounted at the predetermined position.
After that, fixing the guide bar cramp 7 by a screw 11, the cramp arms 9, 9 are pressed upon the guide bar 6 and thus the inclined angle is widen as shown in the FIG. 5. In this manner, the guide bar 6 is supported by the stress receiving members 2, 3 from one side, and is urged by the cramp arms 9, 9 from the other side, thus is thereby cramped.
Besides, side edge faces of the cramp arms 9, 9 are bent downwards to form stoppers 12 and 12. The stoppers 12, 12 engage to prevent the guide bar 6 from moving in thrust direction by abutting against both edge faces of the guide bar 6. Further, a recess portion 13 is provided on the frame 1 to keep a space for the slide table 4 of the head carriage.
In this structure, a torque according to the screw-tightening works upon the guide bar cramp 7, and there is fear of that the guide bar camp 7 would be twisted (to the right direction in the plan view), wherein the screw 11 is the center of the twist. It makes the guide bar 6 inclined and thereby a shifting direction of the head carriage would be out of the predetermined direction.